/**
 * Software License, Version 1.0
 * 
 * Copyright 2003 The Trustees of Indiana University. All rights reserved.
 * 
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1) All redistributions of source code must retain the above copyright notice,
 * the list of authors in the original source code, this list of conditions and
 * the disclaimer listed in this license; 2) All redistributions in binary form
 * must reproduce the above copyright notice, this list of conditions and the
 * disclaimer listed in this license in the documentation and/or other materials
 * provided with the distribution; 3) Any documentation included with all
 * redistributions must include the following acknowledgement:
 * 
 * "This product includes software developed by the Community Grids Lab. For
 * further information contact the Community Grids Lab at
 * http://communitygrids.iu.edu/."
 * 
 * Alternatively, this acknowledgement may appear in the software itself, and
 * wherever such third-party acknowledgments normally appear.
 * 
 * 4) The name Indiana University or Community Grids Lab or NaradaBrokering,
 * shall not be used to endorse or promote products derived from this software
 * without prior written permission from Indiana University. For written
 * permission, please contact the Advanced Research and Technology Institute
 * ("ARTI") at 351 West 10th Street, Indianapolis, Indiana 46202. 5) Products
 * derived from this software may not be called NaradaBrokering, nor may Indiana
 * University or Community Grids Lab or NaradaBrokering appear in their name,
 * without prior written permission of ARTI.
 * 
 * 
 * Indiana University provides no reassurances that the source code provided
 * does not infringe the patent or any other intellectual property rights of any
 * other entity. Indiana University disclaims any liability to any recipient for
 * claims brought by any other entity based on infringement of intellectual
 * property rights or otherwise.
 * 
 * LICENSEE UNDERSTANDS THAT SOFTWARE IS PROVIDED "AS IS" FOR WHICH NO
 * WARRANTIES AS TO CAPABILITIES OR ACCURACY ARE MADE. INDIANA UNIVERSITY GIVES
 * NO WARRANTIES AND MAKES NO REPRESENTATION THAT SOFTWARE IS FREE OF
 * INFRINGEMENT OF THIRD PARTY PATENT, COPYRIGHT, OR OTHER PROPRIETARY RIGHTS.
 * INDIANA UNIVERSITY MAKES NO WARRANTIES THAT SOFTWARE IS FREE FROM "BUGS",
 * "VIRUSES", "TROJAN HORSES", "TRAP DOORS", "WORMS", OR OTHER HARMFUL CODE.
 * LICENSEE ASSUMES THE ENTIRE RISK AS TO THE PERFORMANCE OF SOFTWARE AND/OR
 * ASSOCIATED MATERIALS, AND TO THE PERFORMANCE AND VALIDITY OF INFORMATION
 * GENERATED USING SOFTWARE.
 */
package cgl.narada.discovery.broker;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Hashtable;
import java.util.Properties;
import java.util.Random;

import org.apache.log4j.Logger;

import cgl.narada.event.NBEvent;
import cgl.narada.event.TemplateProfileAndSynopsisTypes;
import cgl.narada.matching.Profile;
import cgl.narada.protocol.ProtocolHandler;
import cgl.narada.service.ServiceException;
import cgl.narada.service.client.ClientService;
import cgl.narada.service.client.EventConsumer;
import cgl.narada.service.client.EventProducer;
import cgl.narada.service.client.NBEventListener;
import cgl.narada.service.client.SessionService;

/**
 * Functions asa client within the broker node. The function of this object is
 * to forward all discovery requests to other brokers who might be in the
 * system. Further on recieving a BrokerDiscovery request, we chech for the last
 * 'N' requests (configured in config/BrokerConfiguration.txt using the
 * MAXBrokerDiscoRequests parameter) <br>
 * Created on Mar 30, 2005
 * 
 * @author Harshawardhan Gadgil (hgadgil@grids.ucs.indiana.edu)
 */

public class BrokerDiscoveryRequestForwardingService implements NBEventListener {

    static Logger log = Logger
            .getLogger("BrokerDiscoveryRequestForwardingService");

    public static final String BROKER_DISCOVERY_REQUEST_TOPIC = "Services/BrokerDiscovery";

    private EventConsumer consumer;
    private EventProducer producer;

    private ProtocolHandler protocolHandler;

    private Profile profile;

    private ClientService clientService;

    public BrokerDiscoveryRequestForwardingService(
            ProtocolHandler _protocolHandler, String configFileLocation) {
        Properties prop = new Properties();

       protocolHandler = _protocolHandler;

        try {
            prop.put("hostname", InetAddress.getLocalHost().getHostAddress());
        } catch (UnknownHostException e) {
            prop.put("hostname", "localhost");
        }

        // Check from the params

        Hashtable protocols = protocolHandler.getSupportedTransportProtocols();

        boolean connected = false;

        String transportType = null;

        if (protocols.containsKey("niotcp")) {
            transportType = "niotcp";
            Properties niotcpProps = (Properties) protocols.get(transportType);
            String niotcpPort = niotcpProps.getProperty("NIOTCPServerPort");
            prop.put("portnum", niotcpPort);

	    connected = tryConnect("niotcp", prop, configFileLocation);
        } 

        if (!connected && protocols.containsKey("tcp")) {
            transportType = "tcp";
            Properties tcpProps = (Properties) protocols.get(transportType);
            String tcpPort = tcpProps.getProperty("TCPServerPort");
            prop.put("portnum", tcpPort);

	    connected = tryConnect("tcp", prop, configFileLocation);
        } 

        if (!connected && protocols.containsKey("udp")) {
            transportType = "udp";
            Properties udpProps = (Properties) protocols.get(transportType);
            String udpPort = udpProps.getProperty("UDPListenerPort");
            prop.put("portnum", udpPort);

	    connected = tryConnect("udp", prop, configFileLocation);
        } 


        if(!connected) {
		log.error("Could not initialize BrokerDiscoveryRequestForwardingService forwarding !");
        }        
    }

    private boolean tryConnect(String transportType, Properties prop, String configFileLocation) {
     
        // IMP: Might conflict w/ other ppl's entity IDs Maintain constant for
        // now
        int entityId = (new Random()).nextInt();

               
        String info = "Connecting using " + transportType + "@ " +
            prop.getProperty("hostname") + ":" + prop.getProperty("portnum") + 
            "  EntityID [" + entityId + "]";
        log.info(info);
        
        try {
            clientService = SessionService.getClientService(entityId,
                    configFileLocation);

            clientService.initializeBrokerCommunications(prop, transportType);
            profile = clientService.createProfile(
                    TemplateProfileAndSynopsisTypes.STRING,
                    BROKER_DISCOVERY_REQUEST_TOPIC);
            consumer = clientService.createEventConsumer(this);

            consumer.subscribeTo(profile);

            producer = clientService.createEventProducer();
            producer.setSuppressRedistributionToSource(true);
            producer.generateEventIdentifier(true);
            producer.setTemplateId(12345);
            producer.setDisableTimestamp(false);
	
	    return true;
        } catch (ServiceException e) {
            log.error("Unable to Connect to local broker using: " + transportType);
	    log.warn("Discovery Service may not run properly.");
            return false;
        }
    }

    public void shutdown() {
	if(consumer == null) {
		return;
	}

        try {
            consumer.unSubscribe(profile);
            clientService.closeBrokerConnection();
            clientService.terminateServices();
        } catch (ServiceException e) {
            // Ignore error
        }

    }

    public void forwardRequest(byte[] request) {
        try {
            NBEvent nbEvent = producer.generateEvent(
                    TemplateProfileAndSynopsisTypes.STRING,
                    BROKER_DISCOVERY_REQUEST_TOPIC, request);
            producer.publishEvent(nbEvent);
        } catch (ServiceException e) {
            log.error("", e);
        }
    }

    public void onEvent(NBEvent nbEvent) {
        byte[] discoRequest = nbEvent.getContentPayload();

        // DO not forward the request to other brokers. This eliminates flooding
        protocolHandler.processBrokerDiscoveryRequest(discoRequest, false);
    }
}
